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Introduction:accurate and timely laboratory diagnosis of yellow fever (YF) is critical to the Eliminate Yellow Fever Epidemics (EYE) strategy. Gavi, the Vaccine Alliance recognized the need to support and build capacity in the national and regional laboratories in the Global YF Laboratory Network (GYFLN) as part of this strategy. Methods:to better understand current capacity, gaps and needs of the GYFLN laboratories in Africa, assessments were carried out in national and regional reference laboratories in the 25 African countries at high risk for YF outbreaks that were eligible for new financial support from Gavi. Results:the assessments found that the GYFLN in Africa has high capacity but 21% of specimens were not tested due to lack of testing kits or reagents and approximately 50% of presumptive YF cases were not confirmed at the regional reference laboratory due to problems with shipping. Conclusion:the laboratory assessments helped to document the baseline capacities of these laboratories prior to Gavi funding to support strengthening YF laboratories.

Litter falls and their contributions to soil nutriments were measured in five distinct facies of a mangrove in French Guyana. These facies were characterized by their distance from the sea, their floral composition (Laguncularia racemosa (L.), Avicennia germinans (L.) Stearn, Rhizophora spp.), and their structural features. Data were analyzed according to facies and to species for litters, as well as to seasons for the nutriments. This mangrove produced respectively 8.8 and 8.7 t·ha–1·year–1 of litter at the pioneer and senescent stages submitted to strong environmental constraint and 12.5 and 12.6 t·ha–1·year–1 for young and mature stages where developmental conditions are optimum. Nitrogen and carbon inputs were estimated to 1.3 × 10–2 and 6.4 t·ha–1·year–1, respectively. Litter appeared rich in phosphorous, corresponding with the high concentrations characterizing the sediments. For a given species, magnesium and calcium concentrations were constant between facies, whereas potassium and sodium concentrations varied according to the distance from the sea. Differences were perceived between species for all nutriments except sodium. Results are discussed in relation with the ecophysiological characteristics of the mangrove trees and the specific sedimentology of Guyana coast and are replaced in the perspective of an improved knowledge of the carbon and mineral balances in tropical coastal ecosystems.Key words: mangrove, French Guyana, litter, carbon balance, mineral nutriments, spatial variations.[Journal translation]

West Nile virus ecology has yet to be rigorously investigated in the Caribbean Basin. We identified a transmission focus in Puerto Barrios, Guatemala, and established systematic monitoring of avian abundance and infection, seroconversions in domestic poultry, and viral infections in mosquitoes. West Nile virus transmission was detected annually between May and October from 2005 to 2008. High temperature and low rainfall enhanced the probability of chicken seroconversions, which occurred in both urban and rural sites. West Nile virus was isolated from Culex quinquefasciatus and to a lesser extent, from Culex mollis/Culex inflictus, but not from the most abundant Culex mosquito, Culex nigripalpus. A calculation that combined avian abundance, seroprevalence, and vertebrate reservoir competence suggested that great-tailed grackle (Quiscalus mexicanus) is the major amplifying host in this ecosystem. West Nile virus transmission reached moderate levels in sentinel chickens during 2007, but less than that observed during outbreaks of human disease attributed to West Nile virus in the United States.

The role wild bird species play in the transmission and ecology of avian influenza virus (AIV) is well established; however, there are significant gaps in our understanding of the worldwide distribution of these viruses, specifically about the prevalence and/or significance of AIV in Central and South America. As part of an assessment of the ecology of AIV in Guatemala, we conducted active surveillance in wild birds on the Pacific and Atlantic coasts. Cloacal and tracheal swab samples taken from resident and migratory wild birds were collected from February 2007 to January 2010.1913 samples were collected and virus was detected by real time RT-PCR (rRT-PCR) in 28 swab samples from ducks (Anas discors). Virus isolation was attempted for these positive samples, and 15 isolates were obtained from the migratory duck species Blue-winged teal. The subtypes identified included H7N9, H11N2, H3N8, H5N3, H8N4, and H5N4. Phylogenetic analysis of the viral sequences revealed that AIV isolates are highly similar to viruses from the North American lineage suggesting that bird migration dictates the ecology of these viruses in the Guatemalan bird population.

We studied structural and diversity in two types characteristic of French Guiana - the mangrove and the dense forest on well drained soil. Large-scale aerial photographs in digital (black & white) and analogue (color slides) format, acquired at several altitudes ranging from 100 to 1500 meters, were used. In the mangrove (Marais Leblond), which has a poor floristic composition and undergoes continuous change, we focused on the structural diversity of the different stages in relation to ecosystem diversity. In the dense forest (Paracou), much richer in number of species, we focused on tree crown diversity in the canopy, linked to taxa diversity (species, genus, family). Through these two examples, mangrove and dense forest, large-scale aerial photographs were shown to be an effective tool in studying biodiversity in Guianese forests and in understanding how they function. The proposed methods, concerning photograph acquisition and analyses alike, should be implemental in defining policies for management and conservation of biodiversity, Nous abordons ici l'étude de la diversité structurale et floristique dans deux formations forestières caractéristiques de la Guyane française : la mangrove et la forêt dense sur sol drainé. Des photographies aériennes à grande échelle, numériques (noir et blanc) et analogiques (diapositives couleur), acquises à des altitudes variant de 1 00 à 1 500 m, ont été utilisées. Dans la mangrove (Marais Leblond), formation floristiquement simple et en évolution rapide, on s'est principalement attaché à l'étude de la diversité des faciès structuraux liée à la dynamique du milieu. Dans la forêt dense (Paracou), beaucoup plus riche en espèces, l'accent a été mis sur la diversité des couronnes d'arbres dans la canopée associée à la diversité des taxons (espèces, genres, familles). A travers ces deux exemples, mangrove et forêt dense, la photographie aérienne à grande échelle est apparue comme un outil performant pour la reconnaissance de la biodiversité des forêts guyanaises et l'aide à la compréhension de leur fonctionnement. Les méthodes mises en place, tant pour les aspects techniques d'acquisition des photographies que pour leur analyse, doivent permettre, à terme, de définir des stratégies de gestion et de conservation de cette biodiversité., Trichon Valérie, Guillemyn Daniel, Fromard François, Betoulle Jean-Luc, Puig Henri. La photographie aérienne à grande échelle : un outil pour l'analyse de la diversité en forêt guyanaise. In: Journal d'agriculture traditionnelle et de botanique appliquée, 40ᵉ année, bulletin n°1-2,1998. Conserver, gérer la biodiversité : quelle stratégie pour la Guyane ? sous la direction de Marie Fleury et Odile Poncy. pp. 405-421.